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vm: several improvements to VMUserAddressSpace::_InsertAreaSlot implementation

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* B_BASE_ADDRESS honors requested alignment
 * end of range is honored
 * B_BASE_ADDRESS reuses B_ANY_ADDRESS code
This commit is contained in:
Pawel Dziepak 2013-04-04 20:56:41 +02:00
parent a8f8d2c057
commit d57105534b
1 changed files with 45 additions and 82 deletions
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127
src/system/kernel/vm/VMUserAddressSpace.cpp
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@ -186,10 +186,6 @@ VMUserAddressSpace::InsertArea(VMArea* _area, size_t size,
case B_ANY_KERNEL_BLOCK_ADDRESS:
case B_RANDOMIZED_ANY_ADDRESS:
searchBase = fBase;
// TODO: remove this again when vm86 mode is moved into the kernel
// completely (currently needs a userland address space!)
if (searchBase == USER_BASE)
searchBase = USER_BASE_ANY;
searchEnd = fEndAddress;
break;
@ -202,6 +198,11 @@ VMUserAddressSpace::InsertArea(VMArea* _area, size_t size,
return B_BAD_VALUE;
}
// TODO: remove this again when vm86 mode is moved into the kernel
// completely (currently needs a userland address space!)
if (addressRestrictions->address_specification != B_EXACT_ADDRESS)
searchBase = max_c(searchBase, USER_BASE_ANY);
status = _InsertAreaSlot(searchBase, size, searchEnd,
addressRestrictions->address_specification,
addressRestrictions->alignment, area, allocationFlags);
@ -603,17 +604,21 @@ second_chance:
case B_ANY_KERNEL_ADDRESS:
case B_ANY_KERNEL_BLOCK_ADDRESS:
case B_RANDOMIZED_ANY_ADDRESS:
case B_BASE_ADDRESS:
case B_RANDOMIZED_BASE_ADDRESS:
case B_RANDOMIZED_IMAGE_ADDRESS:
{
// find a hole big enough for a new area
if (last == NULL) {
// see if we can build it at the beginning of the virtual map
addr_t alignedBase = ROUNDUP(start, alignment);
addr_t nextBase = next == NULL ? end : next->Base();
addr_t nextBase = next == NULL ? end : min_c(next->Base(), end);
if (is_valid_spot(start, alignedBase, size, nextBase)) {
addr_t rangeEnd = min_c(nextBase - size, end);
if (is_randomized(addressSpec)) {
alignedBase = _RandomizeAddress(alignedBase,
nextBase - size, alignment);
alignedBase = _RandomizeAddress(alignedBase, rangeEnd,
alignment);
}
foundSpot = true;
@ -626,15 +631,17 @@ second_chance:
}
// keep walking
while (next != NULL) {
while (next != NULL && next->Base() + size - 1 <= end) {
addr_t alignedBase = ROUNDUP(last->Base() + last->Size(),
alignment);
addr_t nextBase = min_c(end, next->Base());
if (is_valid_spot(last->Base() + (last->Size() - 1),
alignedBase, size, next->Base())) {
alignedBase, size, nextBase)) {
addr_t rangeEnd = min_c(nextBase - size, end);
if (is_randomized(addressSpec)) {
alignedBase = _RandomizeAddress(alignedBase,
next->Base() - size, alignment);
rangeEnd, alignment);
}
foundSpot = true;
@ -663,6 +670,24 @@ second_chance:
foundSpot = true;
area->SetBase(alignedBase);
break;
} else if (addressSpec == B_BASE_ADDRESS
|| addressSpec == B_RANDOMIZED_BASE_ADDRESS
|| addressSpec == B_RANDOMIZED_IMAGE_ADDRESS) {
// we didn't find a free spot in the requested range, so we'll
// try again without any restrictions
start = USER_BASE_ANY;
if (!is_randomized(addressSpec))
addressSpec = B_ANY_ADDRESS;
else if (start == originalStart)
addressSpec = B_RANDOMIZED_ANY_ADDRESS;
else {
start = originalStart;
addressSpec = B_RANDOMIZED_BASE_ADDRESS;
}
last = NULL;
goto second_chance;
} else if (area->id != RESERVED_AREA_ID) {
// We didn't find a free spot - if there are any reserved areas,
// we can now test those for free space
@ -673,7 +698,8 @@ second_chance:
if (next->id != RESERVED_AREA_ID) {
last = next;
continue;
}
} else if (next->Base() + size - 1 > end)
break;
// TODO: take free space after the reserved area into
// account!
@ -694,9 +720,10 @@ second_chance:
&& alignedBase == next->Base()
&& next->Size() >= size) {
addr_t rangeEnd = min_c(next->Size() - size, end);
if (is_randomized(addressSpec)) {
alignedBase = _RandomizeAddress(next->Base(),
next->Size() - size, alignment);
rangeEnd, alignment);
}
addr_t offset = alignedBase - next->Base();
@ -711,7 +738,7 @@ second_chance:
}
if (is_valid_spot(next->Base(), alignedBase, size,
next->Base() + (next->Size() - 1))) {
min_c(next->Base() + next->Size() - 1, end))) {
// The new area will be placed at the end of the
// reserved area, and the reserved area will be resized
// to make space
@ -726,8 +753,11 @@ second_chance:
startRange = max_c(startRange, alignedNextBase);
addr_t rangeEnd
= min_c(next->Base() + next->Size() - size,
end);
alignedBase = _RandomizeAddress(startRange,
next->Base() + next->Size() - size, alignment);
rangeEnd, alignment);
} else {
alignedBase = ROUNDDOWN(
next->Base() + next->Size() - size, alignment);
@ -743,77 +773,10 @@ second_chance:
last = next;
}
}
break;
}
case B_BASE_ADDRESS:
case B_RANDOMIZED_BASE_ADDRESS:
case B_RANDOMIZED_IMAGE_ADDRESS:
{
// find a hole big enough for a new area beginning with "start"
if (last == NULL) {
// see if we can build it at the beginning of the specified
// start
if (next == NULL || next->Base() > start + (size - 1)) {
foundSpot = true;
area->SetBase(start);
break;
}
last = next;
next = it.Next();
}
// keep walking
while (next != NULL) {
if (next->Base() - (last->Base() + last->Size()) >= size) {
// we found a spot (it'll be filled up below)
break;
}
last = next;
next = it.Next();
}
addr_t lastEnd = last->Base() + (last->Size() - 1);
if (next != NULL || end - lastEnd >= size) {
// got a spot
foundSpot = true;
if (lastEnd < start)
area->SetBase(start);
else {
start = lastEnd + 1;
if (is_randomized(addressSpec)) {
addr_t spaceEnd = end;
if (next != NULL)
spaceEnd = next->Base();
start = _RandomizeAddress(lastEnd + 1, spaceEnd - size,
B_PAGE_SIZE);
}
area->SetBase(start);
}
break;
}
// we didn't find a free spot in the requested range, so we'll
// try again without any restrictions
if (!is_randomized(addressSpec)) {
start = fBase;
addressSpec = B_ANY_ADDRESS;
} else if (originalStart == 0) {
start = fBase;
addressSpec = B_RANDOMIZED_ANY_ADDRESS;
} else {
start = originalStart;
originalStart = 0;
}
last = NULL;
goto second_chance;
}
case B_EXACT_ADDRESS:
// see if we can create it exactly here
if ((last == NULL || last->Base() + (last->Size() - 1) < start)